In the field of an electrophotographic image forming apparatus, such as a copying machine, a printer, etc., microscopic particulate toner (developer) has been in use. In the case of an image forming apparatus such as those mentioned above, as developer is consumed, the image forming apparatus is replenished with the developer in a developer supply container removably set in the image forming apparatus. Developer is an extremely fine particulate substance. Thus, if it is mishandled during a developer replenishment operation, it is possible that the developer will scatter. Therefore, there have been proposed developer replenishment methods which place a developer supply container in an image forming apparatus and discharges the developer in the developer supply container, little by little, through a tiny opening of the developer supply container. Further, some of these methods have been put to practical use.
There have been also proposed a large number of cylindrical developer supply containers (conventional container), in which a stirring member (discharging member) for conveying the developer while stirring it, is disposed.
A developer supply container, such as those described above, is provided with a coupling member for driving the stirring member disposed in the developer supply container. The coupling member of a conventional developer supply container is structured so that it receives driving force from the main assembly of an image forming apparatus by engaging with the coupling member of the main assembly.
After the completion of the mounting (insertion) of the above-described developer supply container into the image forming apparatus, a user is to rotate the developer supply container by a preset angle. As the developer supply container is rotated by the preset angle, it becomes possible for the developer supply container to perform its operation (developer replenishment operation). That is, as the developer supply container is rotated, the hole with which the peripheral surface of the developer supply container is provided becomes connected to the developer receiving hole of the image forming apparatus, making it possible for the image forming apparatus to be replenished with the developer.
The apparatus disclosed in Japanese Laid-open Patent Application H53-46040 is structured so that an operation, such as the above-described one, for rotating a developer supply container to set it for developer discharge, is automatically carried out.
More concretely, as the coupling member for driving the stirring member disposed in the developer supply container receives a driving force by engaging with the coupling member of the image forming apparatus, the step for rotating the developer supply container to set it for developer delivery is carried out.
Thus, in the case of the apparatus disclosed in the above-mentioned governmental gazette, it is reasonable to think that because the developer supply container is set for developer discharge by being rotated, there is provided a structural arrangement for making it rather difficult for the coupling member of the developer supply container to be rotated relative to the container proper of the developer supply container. In other words, it is reasonable to think that even after the developer supply container is properly set for developer discharge by being rotated, the coupling member of the developer supply container remains under a substantial amount of torsional load.
That is, in the case of the apparatus disclosed in the above-mentioned governmental gazette, even during the process for supplying the image forming apparatus with the developer, which is carried out after the developer supply container is properly set in the image forming apparatus by being rotated, the amount of force necessary for driving the coupling member remains substantial.
Therefore, in the case of the apparatus disclosed in the above-mentioned governmental gazette, the amount of force necessary to drive the stirring member to replenish the developer supply container with the developer is substantial, and therefore, the amount of load, to which the driving motor, driving gear, etc., for driving the stirring member is subjected, is substantial.